Role of peripheral quantitative computed tomography in identifying disuse osteoporosis in paraplegia

Objective: Disuse osteoporosis is a major long-term health consequence of spinal cord injury (SCI) that still needs to be addressed. Its management in SCI should begin with accurate diagnosis, followed by targeted treatments in the most vulnerable subgroups. We present data quantifying disuse osteoporosis in a cross-section of the Scottish paraplegic population to identify subgroups with lowest bone mineral density (BMD). Materials and Methods: Forty-seven people with chronic SCI at levels T2-L2 were scanned using peripheral Quantitative Computed Tomography (pQCT) at four tibial sites and two femoral sites, at the Queen Elizabeth National Spinal Injuries Unit, Glasgow (U.K.). At the distal epiphyses, trabecular BMD (BMDtrab), total BMD, total bone cross-sectional area (CSA), and bone mineral content (BMC) were determined. In the diaphyses, cortical BMD, total bone CSA, cortical CSA, and BMC were calculated. Bone, muscle and fat CSAs were estimated in the lower leg and thigh. Results: BMDtrab decreased exponentially with time since injury, at different rates in the tibia and femur. At most sites, female paraplegics had significantly lower BMC, total bone CSA and muscle CSA than male paraplegics. Subjects with lumbar SCI tended to have lower bone values and smaller muscle CSAs than in thoracic SCI. Conclusion: At the distal epiphyses of the tibia and femur, there is generally a rapid and extensive reduction in BMDtrab after SCI. Female subjects, and those with lumbar SCI, tend to have lower bone values than males or those with thoracic SCI, respectively. Keywords: Bone loss, osteoporosis, paraplegia, peripheral Quantitative Computed Tomography, spinal cord injur

Transparent metal electrodes from ordered nanosphere arrays

We show that perforated metal electrode arrays, fabricated using nanosphere lithography, provide a viable alternative to conductive metal oxides as transparent electrode materials. The inter-aperture spacing is tuned by varying etching times in an oxygen plasma, and the effect of inter-aperture “wire” thickness on the optical and electronic properties of perforated silver films is shown. Optical transmission is limited by reflection and surface plasmons, and for these results do not exceed 73%. Electrical sheet resistance is shown to be as low as 3 Ω ◻−1 for thermally evaporated silver films. The performance of organic photovoltaic devices comprised of a P3HT:PCBM bulk heterojunction deposited onto perforated metal arrays is shown to be limited by optical transmission, and a simple model is presented to overcome these limitations

The Size of the Narrow-Line Emitting Region in the Seyfert 1 Galaxy NGC 5548 from Emission-Line Variability

The narrow [O III] 4959, 5007 emission-line fluxes in the spectrum of the well-studied Seyfert 1 galaxy NGC 5548 are shown to vary with time. From this we show that the narrow line-emitting region has a radius of only 1-3 pc and is denser (n ~ 10^5 cm^{-3}) than previously supposed. The [O III] line width is consistent with virial motions at this radius given previous determinations of the black hole mass.Since the [O III] emission-line flux is usually assumed to be constant and is therefore used to calibrate spectroscopic monitoring data, the variability has ramifications for the long-term secular variations of continuum and emission-line fluxes, though it has no effect on shorter-term reverberation studies. We present corrected optical continuum and broad Hbeta emission-line light curves for the period 1988 to 2008.Comment: 11 pages, 5 figures, 6 tables. Accepted for publication in Ap

Mediating punitiveness: understanding public attitudes towards work-related fatality cases

This paper concerns an empirical investigation into public attitudes towards work-related fatality cases, where organizational offenders cause the death of workers or members of the public. This issue is particularly relevant following the introduction of the Corporate Manslaughter and Corporate Homicide Act 2007 into UK law. Here, as elsewhere, the use of criminal law against companies reflects governmental concerns over public confidence in the law’s ability to regulate risk. The empirical findings demonstrate that high levels of public concern over these cases do not translate into punitive attitudes. Such cases are viewed rationally and constructively, and lead to instrumental rather than purely expressive enforcement preferences

Effect of structural ordering of the carbon support on the behavior of Pd catalysts in aqueous-phase hydrodechlorination

Catalysts consisting of Pd supported on virgin and heat-treated carbon blacks (homemade and commercial), graphites (natural and synthetic) and commercial carbon nanofibers were prepared and tested in the aqueous phase hydrodechlorinaton (HDC) of 4-chlorophenol (4-CP) under near ambient conditions (30 °C, 1 atm) in order to explore the effect of the support on the catalytic behavior. The homemade graphitized supports were prepared from commercial carbon black (CB) and from a carbon black-like material (CBPE) obtained from pyrolysis of low-density polyethylene. All the catalysts prepared yielded complete 4-CP conversion, although a wide range of activity was observed (10.7–173.5 mmol gPd−1 min−1). The graphitized carbon black provided the most active catalysts, showing Pd nanoparticles around 3 nm in size and a well-balanced contribution of Pd species (Pdn+/Pd0 = 0.9). Substantial differences of activity were found between the graphitized and not graphitized supports, even for catalysts with similar Pd nanoparticle size. The higher activity of the catalysts with graphitized supports can be partly associated to a more balanced initial Pdn+ to Pd0 ratio. Moreover, higher selectivity to hydrogenation products (cyclohexanone) was also achieved with those catalysts due to a higher contribution of the Pd0 speciesThe authors greatly appreciate financial support from the Spanish MINECO (CTQ2012-32821

Editorial: Green chemistry biocatalysis

Editorial on the Research Topic: Green chemistry biocatalysi

Solution of the Bosonic and Algebraic Hamiltonians by using AIM

We apply the notion of asymptotic iteration method (AIM) to determine eigenvalues of the bosonic Hamiltonians that include a wide class of quantum optical models. We consider solutions of the Hamiltonians, which are even polynomials of the fourth order with the respect to Boson operators. We also demonstrate applicability of the method for obtaining eigenvalues of the simple Lie algebraic structures. Eigenvalues of the multi-boson Hamiltonians have been obtained by transforming in the form of the single boson Hamiltonian in the framework of AIM

POEMMA: Probe Of Extreme Multi-Messenger Astrophysics

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) mission is being designed to establish charged-particle astronomy with ultra-high energy cosmic rays (UHECRs) and to observe cosmogenic tau neutrinos (CTNs). The study of UHECRs and CTNs from space will yield orders-of-magnitude increase in statistics of observed UHECRs at the highest energies, and the observation of the cosmogenic flux of neutrinos for a range of UHECR models. These observations should solve the long-standing puzzle of the origin of the highest energy particles ever observed, providing a new window onto the most energetic environments and events in the Universe, while studying particle interactions well beyond accelerator energies. The discovery of CTNs will help solve the puzzle of the origin of UHECRs and begin a new field of Astroparticle Physics with the study of neutrino properties at ultra-high energies.Comment: 8 pages, in the Proceedings of the 35th International Cosmic Ray Conference, ICRC217, Busan, Kore